Some 400 demonstrators shouting anti-US slogans gathered on Saturday in the central Philippine resort of Cebu as leaders of 10 Southeast Asian nations launched their annual summit.
"US out of Southeast Asia" read one banner carried by chanting protesters in the centre of Cebu City, some miles away from the heavily guarded summit venue on Mactan island.
"US number one terrorist!" chanted the demonstrators, many of them from the leftist Bayan Muna party headed by a former communist guerrilla leader.
The demonstrators carried effigies of Philippine President Gloria Arroyo and of a Western figure labelled "Number One Terrorist."
They said they planned later to march to a convention centre hosting some summit side events, in defiance of a national police ban on rallies during the event.
Leaders of the Association of Southeast Asian Nations (ASEAN), some of whom are US allies, were meeting on Saturday.
On Sunday and Monday they will hold summits with China, Japan, South Korea, India, Australia and New Zealand.
The United States itself is not involved in the summits.
Police did not immediately try to halt today's protest. On Friday they dispersed hundreds of activists protesting trade liberalisation and arrested three of them.